You're right. I probably mixed up some facts because I mostly see these cars on hillclimbs, and there almost anything goes.
Also in Italy (close to me), nobody really cares what homologation papers say, so a lot of italian Clio Gr.A are actually more developed then Clio Maxi (even running ITBs, which they shouldn't).
I will correct this on wiki (if nobody did it already)!
Thanks for the input! If you have any other info, please share!